A completion comprises several hardware components. The casing string is built as a long line of tubing parts mounted together by means of casing collars and, to optimise production, valves are built in as part of the casing string.
Sometimes, leaks may occur, which must be found and sealed off if they are not to impair the production. For this purpose, a tool capable of identifying the condition of the well and detecting the leak is required.
During production, the valves have to be opened or closed. However, a valve may be covered by scales or the like, sometimes to an extent which makes operation of the valve impossible, or the valve may be so damaged by previous attempts to operate it that it can no longer be opened or closed by conventional tools. In order to determine whether the valve needs cleaning or whether a new key to operate the valve is needed, a tool which is able to identify the condition of the hardware in the well is required.